Declined trends of chlorophyll a in the South China Sea over 2005–2019 from remote sensing reconstruction

作     者：Tianhao Wang Yu Sun Hua Su Wenfang Lu Tianhao Wang;Yu Sun;Hua Su;Wenfang Lu

作者机构：School of Marine SciencesSun Yat-Sen UniversityZhuhai519000China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai519000China College of Ocean and Earth SciencesXiamen UniversityXiamen361102China State Key Laboratory of Marine Environmental ScienceXiamen UniversityXiamen361102China Key Laboratory of Spatial Data Mining and Information Sharing of Ministry of EducationFuzhou UniversityFuzhou350108China National&Local Joint Engineering Research Center of Satellite Geospatial Information TechnologyFuzhou UniversityFuzhou350108China 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2023年第42卷第1期

页      面：12-24页

核心收录：

学科分类：082803[工学-农业生物环境与能源工程] 08[工学] 0828[工学-农业工程] 0804[工学-仪器科学与技术] 0816[工学-测绘科学与技术] 

基　　金：The National Natural Science Foundation of China under contract No.41906019 

主　　题：chlorophyll a concentration quantile trends remote sensing reconstruction South China Sea 

摘      要：Chlorophyll a concentration(CHL)is an important proxy of the marine ecological environment and phytoplankton ***-term trends in CHL of the South China Sea(SCS)reflect the changes in the ecosystem’s productivity and functionality in the regional carbon *** this study,we applied a previously reconstructed 15-a(2005–2019)CHL product,which has a complete coverage at 4 km and daily resolutions,to analyze the long-term trends of CHL in the *** regression was used to elaborate on the long-term trends of high,median,and low CHL values,as an extended method of conventional linear *** results showed downward trends of the SCS CHL for the 75th,50th,and 25th quantile in the past 15 a,which were−0.0040 mg/(m^(3)·a)(−1.62%per year),−0.0023 mg/(m^(3)·a)(−1.10%per year),and−0.0019 mg/(m^(3)·a)(−1.01%per year).The negative trends in winter(November to March)were more prominent than those in summer(May to September).In terms of spatial distribution,the downward trend was more significant in regions with higher *** led to a reduced standard deviation of CHL over time and *** further explored the influence of various dynamic factors on CHL trends for the entire SCS and two typical systems(winter Luzon Strait(LZ)and summer Vietnam Upwelling System(SV))with single-variate linear regression and multivariate Random Forest *** multivariate analysis suggested the CHL trend pattern can be best explained by the trends of wind speed and mixed-layer *** divergent importance of controlling factors for LZ and SV can explain the different CHL trends for the two *** study expanded our understanding of the long-term changes of CHL in the SCS and provided a reference for investigating changes in the marine ecosystem.